Lecture 8 Optical Sensing. ECE 5900/6900 Fundamentals of Sensor Design
|
|
- Nathaniel Anderson
- 6 years ago
- Views:
Transcription
1 ECE 5900/6900: Fundamentals of Sensor Design Lecture 8 Optical Sensing 1
2 Optical Sensing Q: What are we measuring? A: Electromagnetic radiation labeled as Ultraviolet (UV), visible, or near,mid-, far-infrared (IR) 2 SI Units: Lumen (lm), Lux (lx=lm/m 2 ), Candela (cd)
3 Optical Sensors Photoresistor Photodiode Phototransistor Sparkfun SEN Fairchild QSD2030F Honeywell SDP Thermopile Infrared CMOS Image Sensors Amphenol ZTP-101T Lumex SNR On Semiconductor Samsung KAC S5K9A1
4 Proximity (Distance) Sensing Applications of Optical Sensors 4 Smoke Detector
5 Applications of Optical Sensors Controlling Gas valve with Thermopiles 5 Gas valve in Fireplace Gas valve in Waterheater
6 Smartphone/tablet Camera Applications of Optical Sensors 6 Military Night Vision Camera
7 Types of Optical Sensors 7 Quantum Detectors Photoresistor (Photocell) Photodiode Phototransistor Thermal Detectors Thermopile Image Sensors CMOS Image Sensor
8 Photoelectic Effect Photon absorption and emission of electrons 8 Einstein discovered that when high energy photons interact with electrons, it is possible for the electrons to be ejected from the material Ref:
9 Photoconductive Effect Photon absorption and increase in conductivity 9 Given small bandgap, incident photons can make the electrons jump into the conduction band. The resulting free electrons (and holes) increase conductance and hence lower resistivity of a material
10 Photoresistor (or Photocell or Photoconductor) Light Dependent Resistor (LDR) CdS (Cadmium sulfide) Track Light-controlled variable resistor The resistance of a photoresistor decreases with increasing light intensity An active semiconductor layer (e.g. CdS) that is deposited on an insulating substrate The semiconductor is normally lightly doped Less light-sensitive than photodiodes and phototransistors 10
11 LDR Circuit Example When LDR is exposed to light, LDR resistance is low which makes the base voltage of Q 1 high enough for the collector current to sink As a result LED turns on 11 When LDR is blocked, the resistance goes up (MΩ), and base voltage drops down and shuts off the transistor As a result LED turns off
12 Types of Optical Sensors 12 Quantum Detectors Photoresistor (Photocell) Photodiode Phototransistor Thermal Detectors Thermopile Image Sensors CMOS Image Sensor
13 Photodiode Photodiode p-type material is doped with boron (donor), n-type material is doped with acceptor atoms. When the light energy is greater than the band gap energy, the electrons move into the conduction band creating electron-hole pairs. In the depletion layer the electric field accelerates these electrons toward the n-layer and holes toward the p-layer. This results in a positive charge in the p-layer and a negative charge in the n-layer. If an external circuit is connected between the PN junction, electrons will flow away from n-layer, and holes will flow away from the p-layer 13
14 Photodiode Operation Photodiode Light-controlled current through a diode When exposed to light, electron-hole pairs are created Newly generated electron-hole pairs are swept away by the existing PN junction and current (also known as photo current) is created Must be reverse-biased so that the depletion region is larger Avalanche Phtodiode Solar Cell Mode 14 Photodiode Mode Responsivity (λ) =Photocurrent/Incide nt Light Power
15 Photodiode Model 15 C j R S I PD = Photo Current, I D = Dark Current=Saturation Current=Leakage Current at zero bias, C j =Junction Capacitance, R S =Shunt Resistance of zero-biased PN junction Photoconductive mode: under reverse bias, the measured output current is linearly proportional to the input optical power Photovoltaic mode: under zero bias, the current is held constant vice is restricted and a voltage builds up, dark current is kept at a minimum Ref: thorlabs.us
16 Photodiode Circuit Example Light Detector Circuits based on GaP Photodiode 16 Reverse Bias (improve bandwidth and lower junction capacitance) or Zero Bias (minimum dark current) Ref: thorlabs.us
17 Types of Optical Sensors 17 Quantum Detectors Photoresistor (Photocell) Photodiode Phototransistor Thermal Detectors Thermopile Image Sensors CMOS Image Sensor
18 Photovoltaic Effect Photon absorption and emission of electrons 18 If a high energy photon strikes an electron, the electron can escape into conduction band and creates holes and electrons (free charge carriers)
19 Phototransistor operation Large Base and Collector areas Active region operation Base is left open and is exposed to light Light causes hole electron pairs to be generated This occurs in the reverse biased base-collector junction (BCJ) The hole-electron pairs move under the electric field in the depletion region and provide the base current, causing electrons to be injected into the collector Phototransistor E 19
20 Common-Emitter (CE) Amplifier Phototransistor Example Detect light in near-infrared (λ=700 nm- 1100nm -CE: Current is amplified and Vout is generated -CC: Vout switches from Low to High state 20 Both can be operated in Active or Switch mode Common-Collector (CC) Amplifier Active mode: phototransistor generates a response proportional to the light received Switch mode: phototransistor will either be off (cut-off) or on (saturated) in response to the light.
21 Phototransistor Modes: CC Amplifier Common-Collector (CC) Amplifier (object detection, encoder) 1) Low state to a high state when light is detected 21 2) No light: Vout=0V 3) Light: base current I B is generated, which is amplified by the collector, I C is generated -with R on ~0 Ω, V out =(R E /(R E +R on ))V cc Vout=V cc 4) Mode is set by adusting R E Active Mode (V out propotional to light level): V cc > R E x I C Switch Mode: V cc < R E x I C where I C =max collector current for specific light level Ref:
22 Phototransistor Modes: CE Amplifier Common-Emitter (CE) Amplifier (compare two levels of light) 1) High state to a low state when light is detected 22 2) No light: Vout=V CC 3) Light: base current I B is generated, which is amplified by the collector, I C is generated -with R on ~0 Ω, V out =(R on /(R on +R on ))V cc Vout=0V 4) Mode is set by adusting R C Active Mode (V out propotional to light level): V cc > R C x I C Switch Mode: V cc < R C x I C where I C =max collector current for specific light level Ref:
23 Optocoupler Phototransistor Example Circuit 23 Source signal current passes through the input LED which emits an infra-red light whose intensity is proportional to the electrical signal IR light generates current in the base and it is amplified at the collector. When the current flowing through the LED is interrupted (e.g. digital data), the IR light is cut off and the photo transistor cuts off Optocouplers are used to switch transistors or other components as they provide electrical isolation between a lower voltage control signal and the higher voltage or current output signal. Examples: Microprocessor input/output switching (turn on/off motor, heater, lights), DC and AC power control
24 Types of Optical Sensors 24 Quantum Detectors Photoresistor (Photocell) Photodiode Phototransistor Thermal Detectors Thermopile Image Sensors CMOS Image Sensor
25 Thermopile Basics Thermopile Sensors Thermopiles detect thermal radiation (heat) Thermopile is a chain of serially connected thermocouples*, typically junctions. 25 a: thermopile with a reference temperature sensor attached, x and y are different materials b: micromachined thermopile sensor (note the semiconductor reference temperature sensor on the silicon frame where the cold junctions are deposited) c: sensor in a TO-5 package *Thermocouples:
26 Thermopile Operation Thermopile Thermopile Sensors Example Circuit (Melexis MLX90615) 26 Measure surface temp. of package IR light is absorbed by or emanated from the membrane and temperature of the membrane changes Since the membrane carries hot junctions, the temperature differential with respect to the cold junctions located on the frame generate thermoelectric voltage Membrane may be thermally coupled with a reference temperature sensor or attached to a thermostat having a precisely known temperature Example circuit: measured temp. is amplified and processed via DSP
27 Types of Optical Sensors 27 Quantum Detectors Photoresistor (Photocell) Photodiode Phototransistor Thermal Detectors Thermopile Image Sensors CMOS Image Sensor
28 Image Sensor Basics Charge Coupled Device (CCD) (Tutorial: CCD chip is divided into pixels* Each pixel has a potential well that collects the electrons produced by the photoelectric effect. After the exposure (incoming photons), each pixel has collected a finite amount of electrons (and hence charge) proportional to the amount of light CCD is then read out by cycling the voltages applied to the chip in a process called clocking. Clocking causes the charge in one pixel to be transferred to an adjacent pixel 28 * More at
29 Image Sensor Basics CMOS Image Sensor* Like CCDs, CMOS imagers have an array of photo diodes, one diode within each pixel Unlike CCDs, each pixel in a CMOS imager has its own individual amplifier Each pixel in a CMOS imager can be read directly on an x y coordinate system While a CCD pixel always transfers a charge, a CMOS pixel always detects a photon directly and converts it to a voltage 29 * More in
30 CMOS Image Sensor: An Example On Semiconductor KAC Resolution: 2832 (H) x 2128 (V), 6 megapixel Fabrication Technology: 4.7 μm 5T CMOS 200 MHz DDR at 400 Mbps data rate 30 * More in
Unit 2 Semiconductor Devices. Lecture_2.5 Opto-Electronic Devices
Unit 2 Semiconductor Devices Lecture_2.5 Opto-Electronic Devices Opto-electronics Opto-electronics is the study and application of electronic devices that interact with light. Electronics (electrons) Optics
More informationLecture 18: Photodetectors
Lecture 18: Photodetectors Contents 1 Introduction 1 2 Photodetector principle 2 3 Photoconductor 4 4 Photodiodes 6 4.1 Heterojunction photodiode.................... 8 4.2 Metal-semiconductor photodiode................
More information14.2 Photodiodes 411
14.2 Photodiodes 411 Maximum reverse voltage is specified for Ge and Si photodiodes and photoconductive cells. Exceeding this voltage can cause the breakdown and severe deterioration of the sensor s performance.
More informationFundamentals of CMOS Image Sensors
CHAPTER 2 Fundamentals of CMOS Image Sensors Mixed-Signal IC Design for Image Sensor 2-1 Outline Photoelectric Effect Photodetectors CMOS Image Sensor(CIS) Array Architecture CIS Peripherals Design Considerations
More informationOptical Receivers Theory and Operation
Optical Receivers Theory and Operation Photo Detectors Optical receivers convert optical signal (light) to electrical signal (current/voltage) Hence referred O/E Converter Photodetector is the fundamental
More informationLecture 9 External Modulators and Detectors
Optical Fibres and Telecommunications Lecture 9 External Modulators and Detectors Introduction Where are we? A look at some real laser diodes. External modulators Mach-Zender Electro-absorption modulators
More informationOFCS OPTICAL DETECTORS 11/9/2014 LECTURES 1
OFCS OPTICAL DETECTORS 11/9/2014 LECTURES 1 1-Defintion & Mechanisms of photodetection It is a device that converts the incident light into electrical current External photoelectric effect: Electrons are
More informationLab VIII Photodetectors ECE 476
Lab VIII Photodetectors ECE 476 I. Purpose The electrical and optical properties of various photodetectors will be investigated. II. Background Photodiode A photodiode is a standard diode packaged so that
More information08-2 EE 4770 Lecture Transparency. Formatted 16:41, 12 February 1998 from lsli Steradian. Example
08-1 08-1 Light Definition: wave or particle of electromagnetic energy. Consider photon character of electromagnetic energy. Photon energy, E = ch λ, where c =.9979458 10 9 m s, h =6.660755 10 34 Js, and
More informationChoosing and Using Photo Sensors
Part II Choosing and Using Photo Sensors Selection of the right photo sensor is the first step towards designing an optimal sensor-based system. The second step, and indeed a very important one, is the
More informationPhotons and solid state detection
Photons and solid state detection Photons represent discrete packets ( quanta ) of optical energy Energy is hc/! (h: Planck s constant, c: speed of light,! : wavelength) For solid state detection, photons
More informationComponents of Optical Instruments 1
Components of Optical Instruments 1 Optical phenomena used for spectroscopic methods: (1) absorption (2) fluorescence (3) phosphorescence (4) scattering (5) emission (6) chemiluminescence Spectroscopic
More informationSRM INSTITUTE OF SCIENCE AND TECHNOLOGY (DEEMED UNIVERSITY)
SRM INSTITUTE OF SCIENCE AND TECHNOLOGY (DEEMED UNIVERSITY) QUESTION BANK I YEAR B.Tech (II Semester) ELECTRONIC DEVICES (COMMON FOR EC102, EE104, IC108, BM106) UNIT-I PART-A 1. What are intrinsic and
More informationDetectors for Optical Communications
Optical Communications: Circuits, Systems and Devices Chapter 3: Optical Devices for Optical Communications lecturer: Dr. Ali Fotowat Ahmady Sep 2012 Sharif University of Technology 1 Photo All detectors
More informationOptical Communications
Optical Communications Telecommunication Engineering School of Engineering University of Rome La Sapienza Rome, Italy 2005-2006 Lecture #4, May 9 2006 Receivers OVERVIEW Photodetector types: Photodiodes
More informationMechatronics and Measurement. Lecturer:Dung-An Wang Lecture 2
Mechatronics and Measurement Lecturer:Dung-An Wang Lecture 2 Lecture outline Reading:Ch3 of text Today s lecture Semiconductor 2 Diode 3 4 Zener diode Voltage-regulator diodes. This family of diodes exhibits
More informationOPTI510R: Photonics. Khanh Kieu College of Optical Sciences, University of Arizona Meinel building R.626
OPTI510R: Photonics Khanh Kieu College of Optical Sciences, University of Arizona kkieu@optics.arizona.edu Meinel building R.626 Photodetectors Introduction Most important characteristics Photodetector
More informationCONTENTS. 2.2 Schrodinger's Wave Equation 31. PART I Semiconductor Material Properties. 2.3 Applications of Schrodinger's Wave Equation 34
CONTENTS Preface x Prologue Semiconductors and the Integrated Circuit xvii PART I Semiconductor Material Properties CHAPTER 1 The Crystal Structure of Solids 1 1.0 Preview 1 1.1 Semiconductor Materials
More informationUNIT IX ELECTRONIC DEVICES
UNT X ELECTRONC DECES Weightage Marks : 07 Semiconductors Semiconductors diode-- characteristics in forward and reverse bias, diode as rectifier. - characteristics of LED, Photodiodes, solarcell and Zener
More informationUNIT 3 Transistors JFET
UNIT 3 Transistors JFET Mosfet Definition of BJT A bipolar junction transistor is a three terminal semiconductor device consisting of two p-n junctions which is able to amplify or magnify a signal. It
More informationEnergy band diagrams Metals: 9. ELECTRONIC DEVICES GIST ρ= 10-2 to 10-8 Ω m Insulators: ρ> 10 8 Ω m Semiconductors ρ= 1 to 10 5 Ω m 109 A. Intrinsic semiconductors At T=0k it acts as insulator At room
More informationOPTOELECTRONIC and PHOTOVOLTAIC DEVICES
OPTOELECTRONIC and PHOTOVOLTAIC DEVICES Outline 1. Introduction to the (semiconductor) physics: energy bands, charge carriers, semiconductors, p-n junction, materials, etc. 2. Light emitting diodes Light
More informationPhotodiode: LECTURE-5
LECTURE-5 Photodiode: Photodiode consists of an intrinsic semiconductor sandwiched between two heavily doped p-type and n-type semiconductors as shown in Fig. 3.2.2. Sufficient reverse voltage is applied
More informationChap14. Photodiode Detectors
Chap14. Photodiode Detectors Mohammad Ali Mansouri-Birjandi mansouri@ece.usb.ac.ir mamansouri@yahoo.com Faculty of Electrical and Computer Engineering University of Sistan and Baluchestan (USB) Design
More informationLAB ASSIGNMENT No. 1 Characteristics of IC Temperature Sensor (LM 335)
LAB ASSIGNMENT No. 1 Characteristics of IC Temperature Sensor (LM 335) Equipment Required: ST2302with power supply cord Multi Meter Connecting cords Connection diagram: Temperature Transducers: The most
More informationLecture 7. July 24, Detecting light (converting light to electrical signal)
Lecture 7 July 24, 2017 Detecting light (converting light to electrical signal) Photoconductor Photodiode Managing electrical signal Metal-oxide-semiconductor (MOS) capacitor Charge coupled device (CCD)
More informationKey Questions ECE 340 Lecture 28 : Photodiodes
Things you should know when you leave Key Questions ECE 340 Lecture 28 : Photodiodes Class Outline: How do the I-V characteristics change with illumination? How do solar cells operate? How do photodiodes
More informationEngineering Medical Optics BME136/251 Winter 2018
Engineering Medical Optics BME136/251 Winter 2018 Monday/Wednesday 2:00-3:20 p.m. Beckman Laser Institute Library, MSTB 214 (lab) *1/17 UPDATE Wednesday, 1/17 Optics and Photonic Devices III: homework
More information10/27/2009 Reading: Chapter 10 of Hambley Basic Device Physics Handout (optional)
EE40 Lec 17 PN Junctions Prof. Nathan Cheung 10/27/2009 Reading: Chapter 10 of Hambley Basic Device Physics Handout (optional) Slide 1 PN Junctions Semiconductor Physics of pn junctions (for reference
More informationChapter 3 OPTICAL SOURCES AND DETECTORS
Chapter 3 OPTICAL SOURCES AND DETECTORS 3. Optical sources and Detectors 3.1 Introduction: The success of light wave communications and optical fiber sensors is due to the result of two technological breakthroughs.
More informationFunctional Materials. Optoelectronic devices
Functional Materials Lecture 2: Optoelectronic materials and devices (inorganic). Photonic materials Optoelectronic devices Light-emitting diode (LED) displays Photodiode and Solar cell Photoconductive
More informationLEDs, Photodetectors and Solar Cells
LEDs, Photodetectors and Solar Cells Chapter 7 (Parker) ELEC 424 John Peeples Why the Interest in Photons? Answer: Momentum and Radiation High electrical current density destroys minute polysilicon and
More informationUniversità degli Studi di Roma Tor Vergata Dipartimento di Ingegneria Elettronica. Analogue Electronics. Paolo Colantonio A.A.
Università degli Studi di Roma Tor Vergata Dipartimento di Ingegneria Elettronica Analogue Electronics Paolo Colantonio A.A. 2015-16 Introduction: materials Conductors e.g. copper or aluminum have a cloud
More informationBipolar Junction Transistor (BJT)
Bipolar Junction Transistor (BJT) - three terminal device - output port controlled by current flow into input port Structure - three layer sandwich of n-type and p-type material - npn and pnp transistors
More informationDownloaded from
SOLID AND SEMICONDUCTOR DEVICES (EASY AND SCORING TOPIC) 1. Distinction of metals, semiconductor and insulator on the basis of Energy band of Solids. 2. Types of Semiconductor. 3. PN Junction formation
More informationChapter 16 Other Two-Terminal Devices
Chapter 16 Other Two-Terminal Devices 1 Other Two-Terminal Terminal Devices Schottky diode Varactor diode Power diodes Tunnel diode Photodiode Photoconductive cells IR emitters Liquid crystal displays
More informationCharacterisation of SiPM Index :
Characterisation of SiPM --------------------------------------------------------------------------------------------Index : 1. Basics of SiPM* 2. SiPM module 3. Working principle 4. Experimental setup
More informationSilicon sensors for radiant signals. D.Sc. Mikko A. Juntunen
Silicon sensors for radiant signals D.Sc. Mikko A. Juntunen 2017 01 16 Today s outline Introduction Basic physical principles PN junction revisited Applications Light Ionizing radiation X-Ray sensors in
More informationLED lecture. Wei Chih Wang University of Washington
LED lecture Wei Chih Wang University of Washington Linear and Nonlinear electronics current voltage Vaccum tube (i.e. type 2A3) voltage Thermistor (large negative temperature coefficient of resistivity)
More informationIn the name of God, the most merciful Electromagnetic Radiation Measurement
In the name of God, the most merciful Electromagnetic Radiation Measurement In these slides, many figures have been taken from the Internet during my search in Google. Due to the lack of space and diversity
More informationLecture (09) Bipolar Junction Transistor 3
Lecture (09) Bipolar Junction Transistor 3 By: Dr. Ahmed ElShafee ١ I THE BJT AS AN AMPLIFIER Amplification is the process of linearly increasing the amplitude of an electrical signal and is one of the
More informationElectromagnetic spectrum
Slide 1 Electromagnetic spectrum insert wavelengths of blue to red. 6.071 Optoelectronics 1 Slide 2 Electromagnetic spectrum E = hν = kt e E - Energy k - Plank s constant ν - frequency k - Boltzman s constant
More informationDownloaded from
Question 14.1: In an n-type silicon, which of the following statement is true: (a) Electrons are majority carriers and trivalent atoms are the dopants. (b) Electrons are minority carriers and pentavalent
More informationSEMICONDUCTOR ELECTRONICS: MATERIALS, DEVICES AND SIMPLE CIRCUITS. Class XII : PHYSICS WORKSHEET
SEMICONDUCT ELECTRONICS: MATERIALS, DEVICES AND SIMPLE CIRCUITS Class XII : PHYSICS WKSHEET 1. How is a n-p-n transistor represented symbolically? (1) 2. How does conductivity of a semiconductor change
More informationOptical Amplifiers. Continued. Photonic Network By Dr. M H Zaidi
Optical Amplifiers Continued EDFA Multi Stage Designs 1st Active Stage Co-pumped 2nd Active Stage Counter-pumped Input Signal Er 3+ Doped Fiber Er 3+ Doped Fiber Output Signal Optical Isolator Optical
More informationSimulation of High Resistivity (CMOS) Pixels
Simulation of High Resistivity (CMOS) Pixels Stefan Lauxtermann, Kadri Vural Sensor Creations Inc. AIDA-2020 CMOS Simulation Workshop May 13 th 2016 OUTLINE 1. Definition of High Resistivity Pixel Also
More informationDiodes Rectifiers, Zener diodes light emitting diodes, laser diodes photodiodes, optocouplers
Diodes Rectifiers, Zener diodes light emitting diodes, laser diodes photodiodes, optocouplers Prepared by Scott Robertson Fall 2007 Physics 3330 1 Impurity-doped semiconductors Semiconductors (Ge, Si)
More informationComponents of Optical Instruments
Components of Optical Instruments General Design of Optical Instruments Sources of Radiation Wavelength Selectors (Filters, Monochromators, Interferometers) Sample Containers Radiation Transducers (Detectors)
More informationMicro-sensors - what happens when you make "classical" devices "small": MEMS devices and integrated bolometric IR detectors
Micro-sensors - what happens when you make "classical" devices "small": MEMS devices and integrated bolometric IR detectors Dean P. Neikirk 1 MURI bio-ir sensors kick-off 6/16/98 Where are the targets
More informationDiode conducts when V anode > V cathode. Positive current flow. Diodes (and transistors) are non-linear device: V IR!
Diodes: What do we use diodes for? Lecture 5: Diodes and Transistors protect circuits by limiting the voltage (clipping and clamping) turn AC into DC (voltage rectifier) voltage multipliers (e.g. double
More informationLecture 3: Transistors
Lecture 3: Transistors Now that we know about diodes, let s put two of them together, as follows: collector base emitter n p n moderately doped lightly doped, and very thin heavily doped At first glance,
More informationComponents of Optical Instruments. Chapter 7_III UV, Visible and IR Instruments
Components of Optical Instruments Chapter 7_III UV, Visible and IR Instruments 1 Grating Monochromators Principle of operation: Diffraction Diffraction sources: grooves on a reflecting surface Fabrication:
More informationUNIT-III SOURCES AND DETECTORS. According to the shape of the band gap as a function of the momentum, semiconductors are classified as
UNIT-III SOURCES AND DETECTORS DIRECT AND INDIRECT BAND GAP SEMICONDUCTORS: According to the shape of the band gap as a function of the momentum, semiconductors are classified as 1. Direct band gap semiconductors
More informationSemiconductor Physics and Devices
Metal-Semiconductor and Semiconductor Heterojunctions The Metal-Oxide-Semiconductor Field-Effect Transistor (MOSFET) is one of two major types of transistors. The MOSFET is used in digital circuit, because
More informationElectronic Devices 1. Current flowing in each of the following circuits A and respectively are: (Circuit 1) (Circuit 2) 1) 1A, 2A 2) 2A, 1A 3) 4A, 2A 4) 2A, 4A 2. Among the following one statement is not
More informationProf. Paolo Colantonio a.a
Prof. Paolo olantonio a.a. 2011 12 ipolar transistors are one of the main building blocks in electronic systems They are used in both analogue and digital circuits They incorporate two pn junctions and
More informationADARSH K (ME00362) PRASHANTH S (ME00370) RADHA MALINI M.G (ME00371)
MECHATRONICS PROJECT BY ADARSH K (ME00362) PRASHANTH S (ME00370) RADHA MALINI M.G (ME00371) INDEX Introduction...3 Navigation Principles...3 Line Following Principles...4 Single Sensor...4 Dual Sensor...4
More informationFIBER OPTICS. Prof. R.K. Shevgaonkar. Department of Electrical Engineering. Indian Institute of Technology, Bombay. Lecture: 20
FIBER OPTICS Prof. R.K. Shevgaonkar Department of Electrical Engineering Indian Institute of Technology, Bombay Lecture: 20 Photo-Detectors and Detector Noise Fiber Optics, Prof. R.K. Shevgaonkar, Dept.
More informationDimensions in inches (mm) .021 (0.527).035 (0.889) .016 (.406).020 (.508 ) .280 (7.112).330 (8.382) Figure 1. Typical application circuit.
IL Linear Optocoupler Dimensions in inches (mm) FEATURES Couples AC and DC signals.% Servo Linearity Wide Bandwidth, > khz High Gain Stability, ±.%/C Low Input-Output Capacitance Low Power Consumption,
More informationEE 5611 Introduction to Microelectronic Technologies Fall Thursday, September 04, 2014 Lecture 02
EE 5611 Introduction to Microelectronic Technologies Fall 2014 Thursday, September 04, 2014 Lecture 02 1 Lecture Outline Review on semiconductor materials Review on microelectronic devices Example of microelectronic
More informationObjective Type Questions 1. Why pure semiconductors are insulators at 0 o K? 2. What is effect of temperature on barrier voltage? 3.
Objective Type Questions 1. Why pure semiconductors are insulators at 0 o K? 2. What is effect of temperature on barrier voltage? 3. What is difference between electron and hole? 4. Why electrons have
More informationUNIT VIII-SPECIAL PURPOSE ELECTRONIC DEVICES. 1. Explain tunnel Diode operation with the help of energy band diagrams.
UNIT III-SPECIAL PURPOSE ELECTRONIC DEICES 1. Explain tunnel Diode operation with the help of energy band diagrams. TUNNEL DIODE: A tunnel diode or Esaki diode is a type of semiconductor diode which is
More informationDepartment of Electrical Engineering IIT Madras
Department of Electrical Engineering IIT Madras Sample Questions on Semiconductor Devices EE3 applicants who are interested to pursue their research in microelectronics devices area (fabrication and/or
More informationPhysics 160 Lecture 5. R. Johnson April 13, 2015
Physics 160 Lecture 5 R. Johnson April 13, 2015 Half Wave Diode Rectifiers Full Wave April 13, 2015 Physics 160 2 Note that there is no ground connection on this side of the rectifier! Output Smoothing
More informationDetection Beyond 100µm Photon detectors no longer work ("shallow", i.e. low excitation energy, impurities only go out to equivalent of
Detection Beyond 100µm Photon detectors no longer work ("shallow", i.e. low excitation energy, impurities only go out to equivalent of 100µm) A few tricks let them stretch a little further (like stressing)
More informationMathematics and Science in Schools in Sub-Saharan Africa
Mathematics and Science in Schools in Sub-Saharan Africa SEMICONDUCTORS What is a Semiconductor? What is a Semiconductor? Microprocessors LED Transistors Capacitors Range of Conduciveness The semiconductors
More informationMAHARASHTRA STATE BOARD OF TECHNICAL EDUCATION (Autonomous) (ISO/IEC Certified)
WINTER 16 EXAMINATION Model Answer Subject Code: 17215 Important Instructions to examiners: 1) The answers should be examined by key words and not as word-to-word as given in the model answer scheme. 2)
More informationPHYSICAL ELECTRONICS(ECE3540) APPLICATIONS OF PHYSICAL ELECTRONICS PART I
PHYSICAL ELECTRONICS(ECE3540) APPLICATIONS OF PHYSICAL ELECTRONICS PART I Tennessee Technological University Monday, October 28, 2013 1 Introduction In the following slides, we will discuss the summary
More informationSUMMER 13 EXAMINATION Subject Code: Model Answer Page No: / N
Important Instructions to examiners: 1) The answers should be examined by key words and not as word-to-word as given in the model answer scheme. 2) The model answer and the answer written by candidate
More informationWhere detectors are used in science & technology
Lecture 9 Outline Role of detectors Photomultiplier tubes (photoemission) Modulation transfer function Photoconductive detector physics Detector architecture Where detectors are used in science & technology
More informationUltra-sensitive SiGe Bipolar Phototransistors for Optical Interconnects
Ultra-sensitive SiGe Bipolar Phototransistors for Optical Interconnects Michael Roe Electrical Engineering and Computer Sciences University of California at Berkeley Technical Report No. UCB/EECS-2012-123
More informationElectronic devices-i. Difference between conductors, insulators and semiconductors
Electronic devices-i Semiconductor Devices is one of the important and easy units in class XII CBSE Physics syllabus. It is easy to understand and learn. Generally the questions asked are simple. The unit
More informationField-Effect Transistor (FET) is one of the two major transistors; FET derives its name from its working mechanism;
Chapter 3 Field-Effect Transistors (FETs) 3.1 Introduction Field-Effect Transistor (FET) is one of the two major transistors; FET derives its name from its working mechanism; The concept has been known
More informationIntroduction to Photovoltaics
Introduction to Photovoltaics PHYS 4400, Principles and Varieties of Solar Energy Instructor: Randy J. Ellingson The University of Toledo February 24, 2015 Only solar energy Of all the possible sources
More informationAnalytical Chemistry II
Analytical Chemistry II L3: Signal processing (selected slides) Semiconductor devices Apart from resistors and capacitors, electronic circuits often contain nonlinear devices: transistors and diodes. The
More informationDimensions in inches (mm) .268 (6.81).255 (6.48) .390 (9.91).379 (9.63) .045 (1.14).030 (.76) 4 Typ. Figure 1. Typical application circuit.
LINEAR OPTOCOUPLER FEATURES Couples AC and DC signals.% Servo Linearity Wide Bandwidth, > KHz High Gain Stability, ±.%/C Low Input-Output Capacitance Low Power Consumption, < mw Isolation Test Voltage,
More informationDevelopment of the Pixelated Photon Detector. Using Silicon on Insulator Technology. for TOF-PET
July 24, 2015 Development of the Pixelated Photon Detector Using Silicon on Insulator Technology for TOF-PET A.Koyama 1, K.Shimazoe 1, H.Takahashi 1, T. Orita 2, Y.Arai 3, I.Kurachi 3, T.Miyoshi 3, D.Nio
More informationGamma Spectrometer Initial Project Proposal
Gamma Spectrometer Initial Project Proposal Group 9 Aman Kataria Johnny Klarenbeek Dean Sullivan David Valentine Introduction There are currently two main types of gamma radiation detectors used for gamma
More informationSharjah Indian School, Sharjah ELECTRONIC DEVICES - Class XII (Boys Wing) Page 01
ELECTRONIC DEVICES - Class XII (Boys Wing) Page 01 Electronics is the fast developing branch of Physics. Before the discovery of transistors in 1948, vacuum tubes (thermionic valves) were used as the building
More informationExam Model Answer. Question 1 (15 marks) Answer this question in the form of table. Choose the correct answer (only one answer is accepted).
Benha University Faculty of Engineering Shoubra Electrical Engineering Department First Year Communications. Answer all the following questions Illustrate your answers with sketches when necessary. The
More informationTransistor Characteristics
Transistor Characteristics Topics covered in this presentation: Transistor Construction Transistor Operation Transistor Characteristics 1 of 15 The Transistor The transistor is a semiconductor device that
More informationProblem 4 Consider a GaAs p-n + junction LED with the following parameters at 300 K: Electron diusion coecient, D n = 25 cm 2 =s Hole diusion coecient
Prof. Jasprit Singh Fall 2001 EECS 320 Homework 7 This homework is due on November 8. Problem 1 An optical power density of 1W/cm 2 is incident on a GaAs sample. The photon energy is 2.0 ev and there is
More informationSolar Cell Parameters and Equivalent Circuit
9 Solar Cell Parameters and Equivalent Circuit 9.1 External solar cell parameters The main parameters that are used to characterise the performance of solar cells are the peak power P max, the short-circuit
More informationCoherent Receivers Principles Downconversion
Coherent Receivers Principles Downconversion Heterodyne receivers mix signals of different frequency; if two such signals are added together, they beat against each other. The resulting signal contains
More informationChapter Semiconductor Electronics
Chapter Semiconductor Electronics Q1. p-n junction is said to be forward biased, when [1988] (a) the positive pole of the battery is joined to the p- semiconductor and negative pole to the n- semiconductor
More informationChapter 3-2 Semiconductor devices Transistors and Amplifiers-BJT Department of Mechanical Engineering
MEMS1082 Chapter 3-2 Semiconductor devices Transistors and Amplifiers-BJT Bipolar Transistor Construction npn BJT Transistor Structure npn BJT I = I + E C I B V V BE CE = V = V B C V V E E Base-to-emitter
More informationPhotodiode types. Fig Transistor Optocouplers & Opto Sensors
Module 5 www.learnabout-electronics.org Opto Coupled Devices Module 5.0 What you ll learn in Module 5.0 After studying this section, you should be able to: Opto Devices & Phototransistors Describe the
More informationWhat is the highest efficiency Solar Cell?
What is the highest efficiency Solar Cell? GT CRC Roof-Mounted PV System Largest single PV structure at the time of it s construction for the 1996 Olympic games Produced more than 1 billion watt hrs. of
More informationLAB V. LIGHT EMITTING DIODES
LAB V. LIGHT EMITTING DIODES 1. OBJECTIVE In this lab you are to measure I-V characteristics of Infrared (IR), Red and Blue light emitting diodes (LEDs). The emission intensity as a function of the diode
More informationELECTRONIC DEVICES AND CIRCUITS
ELECTRONIC DEVICES AND CIRCUITS 1. At room temperature the current in an intrinsic semiconductor is due to A. holes B. electrons C. ions D. holes and electrons 2. Work function is the maximum energy required
More informationLecture 12. Bipolar Junction Transistor (BJT) BJT 1-1
Lecture 12 Bipolar Junction Transistor (BJT) BJT 1-1 Course Info Lecture hours: 4 Two Lectures weekly (Saturdays and Wednesdays) Location: K2 Time: 1:40 pm Tutorial hours: 2 One tutorial class every week
More informationDiode Limiters or Clipper Circuits
Diode Limiters or Clipper Circuits Circuits which are used to clip off portions of signal voltages above or below certain levels are called limiters or clippers. Types of Clippers Positive Clipper Negative
More informationInfrared Detectors an overview
Infrared Detectors an overview Mariangela Cestelli Guidi Sinbad IR beamline @ DaFne EDIT 2015, October 22 Frederick William Herschel (1738 1822) was born in Hanover, Germany but emigrated to Britain at
More informationPhysics and Technology
Physics and Technology Emitters Materials Infrared emitting diodes (IREDs) can be produced from a range of different III-V compounds. Unlike the elemental semiconductor silicon, the compound III-V semiconductors
More informationGeorgia Institute of Technology School of Electrical and Computer Engineering. Midterm Exam
Georgia Institute of Technology School of Electrical and Computer Engineering Midterm Exam ECE-3400 Fall 2013 Tue, September 24, 2013 Duration: 80min First name Solutions Last name Solutions ID number
More informationChemistry Instrumental Analysis Lecture 7. Chem 4631
Chemistry 4631 Instrumental Analysis Lecture 7 UV to IR Components of Optical Basic components of spectroscopic instruments: stable source of radiant energy transparent container to hold sample device
More informationLecture 4 -- Tuesday, Sept. 19: Non-uniform injection and/or doping. Diffusion. Continuity/conservation. The five basic equations.
6.012 ELECTRONIC DEVICES AND CIRCUITS Schedule -- Fall 1995 (8/31/95 version) Recitation 1 -- Wednesday, Sept. 6: Review of 6.002 models for BJT. Discussion of models and modeling; motivate need to go
More informationReview Energy Bands Carrier Density & Mobility Carrier Transport Generation and Recombination
Review Energy Bands Carrier Density & Mobility Carrier Transport Generation and Recombination Current Transport: Diffusion, Thermionic Emission & Tunneling For Diffusion current, the depletion layer is
More informationUnit - 19 Semiconductor Electronics
Unit - 19 Semiconductor Electronics 321 Conductor :- Presence of free electrons Electrical resistivity is quite less Insulator :- No free electrons Very large electrical resistivity Semi-conductor :- Hole
More informationSection:A Very short answer question
Section:A Very short answer question 1.What is the order of energy gap in a conductor, semi conductor, and insulator?. Conductor - no energy gap Semi Conductor - It is of the order of 1 ev. Insulator -
More information